I can't find any writing about encouraging this species in the garden so thought I'd write about it. I do live only a few hundred meters from a stream that has glow worms but it seems possible they could find their way to much more remote spots as the adult of this insect can fly. It only lives a few days before laying it's eggs but that might be enough time to cover some distance, they've colonized the whole country after all.
I'm not sure how long it took before they found the spot, the tubs were sitting there for around three years before I noticed their alluring glow, so it may take a while. It's good having them next to a window from which they can be viewed, I might have never noticed them otherwise.The wire mesh in the picture happened to be left there for no reason, interestingly when I took it away they went dark for several days, so I put it back they seemed to get brighter again. Perhaps it reminds them of tree canopy or something else about their natural niche, or perhaps they just don't like change.